WO2021240303A1

WO2021240303A1 - A valve for a fuel cell motor vehicle system

Info

Publication number: WO2021240303A1
Application number: PCT/IB2021/054295
Authority: WO
Inventors: Alessandro Lonati
Original assignee: Omb Saleri S.P.A.
Priority date: 2020-05-29
Filing date: 2021-05-19
Publication date: 2021-12-02

Abstract

A valve (1) for managing the hydrogen flow in a circuit of a fuel cell motor vehicle system comprises a body (2) made of aluminium alloy and a cap portion (16) of a component of the valve (1) made of steel. A sealing ring (24) operates between the cap portion (16) and the wall of the body (2) and the lateral surface (14) of the wall is anodized. Furthermore, there is comprised a separation element (34) made of a plastic material between the cap portion (16) and the wall of the body (2).

Description

DESCRIPTION

"A VALVE FOR A FUEL CELL MOTOR VEHICLE SYSTEM"

[0001]The present invention belongs to the field of components for hydrogen-powered fuel cell motor vehicle systems, designed for installation on board vehicles, such as motor vehicles, commercial vehicles, vehicles for transporting goods and people. In particular, the present invention relates to a valve for adjusting the hydrogen flow in a circuit of the system. [0002]As known, a fuel cell motor vehicle system comprises a tank for storing high-pressure hydrogen, up to 350 or 700bars, a multi-function valve (often referred to as an OTV valve), applied to the tank, a pressure reducing valve (referred to as HPR valve), downstream of the OTV valve, further secondary valves, downstream of the HPR valve, and finally, the fuel cell group for producing an electric current.

[0003]Such valves are generally formed by a body, which, for needs of weight, is made of aluminum. Numerous compartments, passages and seats are made in the body, directly on the semi-finished product or by means of successive machining via removal of swarf, to accommodate the different components of the valve, which is frequently in communication with the external environment by means of an opening on the outer surface of the body. Once the valve has been assembled, such openings are closed by a cap portion, formed, for example, by the portion of a functional component, which serves as a cap, or a real cap. For reasons of mechanical resistance, such cap portion is usually made of steel.

[0004]Due to the elevated pressures at stake, one of the most felt needs in such field is the need to arrange valves having an elevated reliability, so as to avoid undesired hydrogen leaks. Very often, such leaks are due to the occurrence of phenomena of galvanic corrosion, which, as known, occur where two different metals are placed mutually in contact in a humid environment, as is the case between the aluminum body of the valve and the steel cap portion. [0005]It is the object of the present invention to obtain a valve, which satisfies the field needs and overcomes the above drawbacks with reference to the prior art.

[0006]Such an object is achieved by a valve according to claim 1. The dependent claims identify further advantageous embodiments.

[0007]The features and advantages of the valve according to the present invention will become apparent from the description given below, provided by way of a non limiting example, in accordance with the figures in the accompanying drawings, in which: - figure 1 is a partial sectional view of a valve according to an embodiment of the present invention;

- figure 2a shows an enlarged detail of figure 1, which highlights a cap portion of a component of the valve, inserted into a compartment of the valve body;

- figure 2b depicts the compartment of the valve body as indicated in figure 2a;

- figure 3a shows an enlarged detail of figure 1, which highlights a cap portion of a cap of the valve, inserted into a compartment of the valve body;

- figure 3b depicts the compartment of the valve body as indicated in figure 3a.

[0008]With reference to the figures of the accompanying drawings, reference numeral 1 indicates a valve, as a whole, for managing the hydrogen flow in a circuit of a hydrogen-powered fuel cell motor vehicle system.

[0009]For example, the valve 1 is a multifunction valve (OTV valve) applicable to a tank for storing hydrogen, a pressure reducing valve (HPR valve), a proportional valve for adjusting the flow to the fuel cells (HCV valve), a thermally activated safety valve for draining a tank (valve with thermal safety device or valve with TPRD), an anode drain valve (APV valve), a water draining valve

(ADV valve), an electromagnetically operated valve for closing the passage of the gas (HSV valve), and similar. [0010]The valve 1 comprises a body 2 at least partially made of aluminum alloy; the body 2 is preferably made in a single piece, entirely of aluminum alloy, usually obtained by injection molding and successive mechanical machining via removal of swarf.

[0011]Internally, the body 2 has compartments, passages and seats for accommodating components of the valve, which are accessible from the outside by means of an opening 4, 104 present on an outer surface 8 of the body 2. Said compartments, passages and seats are obtained directly on the semi-finished product or they are successively obtained by means of machining via removal of swarf, such as trimming, milling, drilling and similar. [0012]According to an embodiment (figures 2a and 2b), the opening 4 allows access to a compartment 10 delimited circumferentially by an annular compartment wall 12, made of aluminum alloy, having an inner lateral surface 14. The compartment 10 extends along a first central axis X. [0013]For example, internally, the compartment wall 12 has a thread.

[0014]A cap portion 16 of a component of the valve 1 is accommodated in the compartment 10, which is formed, for example, by a support element for a valve 18. The cap portion 16, which closes the opening 4 and has an outer face 16a facing towards the environment outside the body 2, is preferably screwed to the compartment wall 12.

[0015]The cap portion 16 comprises at least one annular peripheral part 20 made of steel, in contact with the compartment wall 12.

[0016]The lateral surface 14 has an annular sealing region 22, which defines, for the compartment 10, an outer region lOe, towards the external environment, and an inner region lOi towards the interior of the body 2. A sealing ring 24 operates on the sealing region 22 adapted to prevent water or vapor or humidity from the external environment from entering in the inner region lOi of the compartment 10.

[0017]The lateral surface 14 further has an annular treatment region 26, which extends from the sealing region 22 towards the exterior, preferably up to the opening 4. The treatment region 26 is subjected to an aluminum anodizing treatment.

[0018]According to a variant, the treatment region also extends on a crown surface 28, which delimits the opening 4; according to yet a further variant, the treatment region also comprises the sealing region 22; according to yet a further variant, the treatment region extends from the sealing region towards the interior of the compartment 10. [0019]Furthermore, a cover 30 is preferably applied to the cap portion 16, at the opening 4.

[0020]In particular, the peripheral part 20 of the cap portion 16 has an end portion 20a, which extends from the outer face 16a towards the interior of the compartment 10, up to the axial position of the sealing region 22. The end portion 20a preferably at least partially overlaps the sealing region 22; furthermore, the end portion 20a preferably extends inwards beyond the sealing region 22.

[0021]The cover 30 is configured to separate the end portion 20a of the peripheral part 20 of the cap portion 16 from the compartment wall 12.

[0022]For example, the cover 30 comprises a plate-shaped base 32, which covers the outer face 16a of the cap portion 16, and an annular separation element 34, which separates the end portion 20a of the peripheral part 20 of the cap portion 16 from the compartment wall 12; said separation element 34 is made of a plastic material. [0023]The cover 30 is preferably made in a single piece, of a plastic material.

[0024]For example, the separation element 34 comprises a peripheral portion 32a of the base 32 and an annular skirt 36 protruding axially from the base 32. [0025]Furthermore, the separation element 34 preferably has a seat 38 for accommodating the sealing ring 24.

[0026]According to a further embodiment (figures 3a and 3b), the opening 104 allows access to a further compartment 110 in which a cap portion 116 is accommodated, made up of a cap, which closes the opening 104. Said embodiment is structurally and functionally similar to the embodiment illustrated previously with reference to figures 2a and 2b.

[0027]Innovatively, the valve according to the present invention satisfies the field needs and overcomes the above drawbacks with reference to the prior art as it avoids the occurrence of phenomena of galvanic corrosion at the openings made on the body of the valve.

[0028]In particular, advantageously, the combination of the sealing ring, which prevents the introduction of water or vapor or humidity, the anodized surface, which protects the aluminum from phenomena of corrosion, and the cover made of a plastic material, which physically separates the aluminum parts from the steel parts in the positions, which are most exposed to corrosion, allows the result to be achieved excellently.

[0029]In particular, according to the invention, it is possible to reduce the extension of the anodized surface to the necessary minimum, which, besides having important production costs for the treatment, does not ensure the low surface roughness and tight machining tolerances necessary for the valves, the subject of the invention. [0030]Clearly, in order to satisfy contingent needs, an expert in the field could make changes to the valve described above, all contained in the scope of protection, as defined by the following claims.

Claims

1. A valve (1) for managing the hydrogen flow in a circuit of a fuel cell motor vehicle system, comprising:

- a body (2) having an outer surface (8) onto which an opening (4,104) opens, allowing access to a compartment (10,110) of the body (2), said compartment (10,110) being delimited circumferentially by an annular compartment wall (12) made of aluminum alloy, having an inner lateral surface (14); - a cap portion (16) of a component of the valve (1), wherein said cap portion (16) closes the opening (4,104) and comprises at least one annular peripheral part (20) made of steel at least partially in contact with the compartment wall (12) of the body (2); wherein i) the lateral surface (14) of the compartment (10,110) has an annular sealing region (22) which defines, for the compartment (10,110), an outer region (lOe) towards the external environment, and an inner region (lOi) towards the interior of the body (2), a sealing ring (24) adapted to prevent water or vapor or humidity from the external environment from entering in the inner region (lOi) of the compartment (10;110); ii) the lateral surface (14) further has an annular treatment region (26), which extends from the sealing region (22) outwards and subjected to an aluminum anodizing treatment; iii) an annular separation element (34) separates an end portion (20a) of the peripheral part (20) of the cap portion (16) from the compartment wall (12), said separation element (34) being made of plastic material.

2. A valve according to claim 1, wherein the compartment wall (12) has a thread for the coupling to the cap portion (16).

3. A valve according to claim 1 or 2, wherein the treatment region also extends over a crown surface (28) which delimits the opening (4,104).

4. A valve according to any one of the preceding claims, wherein the treatment region at least partially overlaps the sealing region (22).

5. A valve according to claim 4, wherein the treatment region comprises the sealing region (22).

6. A valve according to any one of the preceding claims, wherein the treatment region extends from the sealing region towards the interior of the compartment (10).

7. A valve according to any one of the preceding claims, wherein the end portion (20a) extends from an outer face (16a) of the cap portion (16) towards the interior of the compartment (10), up to the axial position of the sealing region (22).

8. A valve according to claim 7, wherein the end portion (20a) at least partially axially overlaps the sealing region (22).

9. A valve according to claim 8, wherein the end portion (20a) extends inwards, beyond the sealing region (22).

10. A valve according to any one of the preceding claims, comprising a cover (30) applied to the cap portion (16) to cover an outer face (16a) of said cap portion (16), said separation element (34) forming part of said cover (30).

11. A valve according to any one of the preceding claims, wherein the separation element (34) has a seat (38) for accommodating the sealing ring (24).